Steam generating and superheating installation



Jan. 25, 1944. 1.. c. SOUTHCOTT 2,340,036

STEAM GENERATING AND SUPERHEAT ING INSTALLATION Filed Oct. 17, 1941IINVENTOR.

BY Zeonald Jaw/k0 g ATTORNEY Patented Jan. 25, 1944 i STEAM GENERATINGAND SUPERHEATIN INSTALLATION 1 Leonard Clement Southcott, Bowdon,Altrincha n,

England, assignor to The superheater Company, New York,..N. Y., acorporation of Delaware Application October 17, 1941, Serial No. 415,378

' In Great Britain October 8, 1940 1 Claim. (01. 122-473) This inventionis concerned with steam 'generating and superheating installations.

Steam generating and superheating installations are known in which thegenerator hasupper and lower drums connected by appropriately baflledbanks of bent water tubes with the space between the banks comprisingtwo water cooled furnaces, there being uptakes at each side of the upperdrum or drums, with convectively heated superheating elements suitablydisposed in the boiler. Such a boiler may be termed doublesided.

Single-sided bent tube boilers also are known having asingle bank ofwater tubes appropriately baflled and connecting upper and lower drums,with a single furnace bounded by water cooled walls and the said tubebank, such a boiler having a convectively heated superheater associatedwith its tube bank.

Boilers of the general kind indicated above are noted for their rapidsteaming, and the present invention seeks to provide a bent tube boilerof such general kind in which a high degree of superheat, or bothsuperheat and reheat, ay be obtained and the superheat temperature, orboth superheat and reheat temperatures, be controlled in a simple andefficient manner.

Broadly stated the invention consists in a boiler having upper and lowerdrums connected by water tubes arranged to form main and subsidiarybanks with two water cooled furnace chambers between them, each with itsown uptake, and between the furnaces a superheater adapted to be heatedby products of combustion passing from the main furnace remote from themain bank into the auxiliary furnace nearer the said bank, there beinganother vapour heater disposed in the said main tube bank, and the steamtemperature being controlled by regulating by means of dampers in therespective uptakes the proportion of the gases from the main furnacewhich flows over the superheater between the furnaces and into theauxiliary furnace and main tube bank, relatively to the proportion whichflows to the uptake directly associated with main furnace.

In carrying the present invention into practice, the vapour heaterlocated in the main tube bank of the boiler may be either a superheaterin series with that between the furnaces, or a reheater; where a secondsuperheater constitutes said vapour heater, control of the final steamtemperature may be effected partly by proportioning the flow of gasesfrom the main furnace to the respec tive uptakes, and thus varying thequantity flowmg over the superheater between the furnaces, and partly byregulating the firing of the auxiliary furnace to control the gas'iiowover such second superheater. v

To define the two furnaces in the furnace space of the boiler a divisionbafile is provided, the superheater disposed between the furnaces beingarranged at the main furnace side of the baffle. This baffle, whilebeing arranged to permit the flow of gases from the main furnace intothe auxiliary furnace, is also such as to cause the gases to flow overthe elements of the superheater lying between the furnaces on their Wayto the auxiliary furnace and main tube bank.

In the accomlpanying drawing- Figure 1 is a sectional elevation andFigure 2 a sectional plan of a boiler with superheating arrangementsaccording to a selected em bodiment of the invention, the illustrationsbeing more or less diagrammatic and Fig. 1 being a section on the linel-I, Fig. 2, while the latter figure is asection on the line 22, Fig. 1.

Referring to the drawing, the steam and water drum 2 is connected toawaterdrum disposed beneath it by bent water tubes forming a main tubebank 3 and a subsidiary tube bank 4. A superheater 5 lies in the furnacespace between the tube banks, and another vapour heater 6, for example arheater, is disposed in the main tube bank 3.

The furnace space is divided by a water cooled baflle into two chambersconstituting a main furnace 1 remote from the main tube bank 3 and anauxiliary furnace 8 nearer said bank, the furnaces being fired byburners at 9 and I0 respectively, in one end wall of the furnace space.The end walls would be cooled by any convenient arrangement of watertubes (not shown).

In the embodiment of the invention illustrated the division bafile l lbetween the furnaces is formed of refractory material supported byvertical water tubes l2, such baffie extending from one end of theboiler an appropriate distance towards the other end, and between theconvectively heated superheater 5, lying adjacent said baffle, and themain furnace 1 one or more rows of spaced vertical water tubes I3 is orare arranged, the latter water tubes and those supporting the bafflebeing available to afford support to the superheater elements.Alternatively, water tubes in contact may be employed, instead ofrefractory material, to form the division bafile.

Associated with the furnaces I, 8 are uptakes [4, I5 respectively,controlled by dampers l6, l1. Gases from the furnaces can flow directlyto lated to control the temperature of steam delivered by the reheater6.

Usually to obtain maximum steam temperature damper l6 would be closedand damper I1 fully opened, whereby the whole of the products ofcombustion from the main furnace I would flow over the superheater 5. 7

To raise pressure in the boiler the main furnace I only would be firedand the products of combustion therefrom would be passed over thesubsidiary tube bank 4 to the uptake l4 associated therewith, the damperI! in the uptake [5- associated with the main tube bank 3 being closed.When sufficient steam is available to protect the elements of thesuperheaters, or superheater and reheater 5, 6 from overheating thedamper H associated with the main tube bank 3 will be opened and gasesfrom the main furnace will flow over the main bank, the damper I6appertaining to the subsidiary bank 4 being closed, or partially closed.At the appropriate time the auxiliary furnace 8 would be fired and thefinal steam temperature; or the final steam and reheat temperatures,will be controlled as already indicated by regulating the gas flow overthe superheaters, or superheater and reheater, by adjusting the dampers,and also by regulating the firing of the auxiliary furnace.

A boiler and vapour heating installation con structed as describedenables the boiler to oper- 3,340,03 1. f if. $11 6:

ate to give a relatively large output of saturated or low temperaturesteam by firing only the main furnace 1 and passing all the productstherefrom over the subsidiary tube bank 4, the damper l1 associated withthe main tube bank 3 being closed.

What I claim is:

- In a boiler having two separate gas offtakes; means formingcommunicating main and auxiliary furnace chambers below said ofitakeseach communicating directly with one of the latter; a superheaterlocated between said furnaces; banks of steam generating tubes locatedbetween the respective furnaces and the oiftake adjacent thereto; bafilemeans positioned between said superheater and said auxiliary furnacechamber so arranged as to shield the superheater from said auxiliarychamber while permitting gases from said main chamber to enter saidauxiliary furnace chamber and pass over the tube bank and to the ofitakewhich are related thereto; fuel burning means associated with said mainfurnace chamber providing the major portion of the heat utilizedin'generating steam in both said tube banks and all of the heat absorbedby said superheater to superheat the steam; other fuel burning meansassociated with said auxiliary furnace chamber providing the remainderof the heat required for absorption in the tube bank between it and itsofitake for generating steam in said boiler; and damper means in saidofitakes operable to regulatethe amount of gases passiiig'from said mainfurnace chamber to the offtake therefor in relation to the amountpassing from, said chamber over said superheater into said auxiliarychamber to be discharged through the offtake for the latter.

LEONARD CLEMENT SOUTHCOTT.

